head JEEP GRAND CHEROKEE 2002 WJ / 2.G Workshop Manual

²Front Check Valve- The front washer system
check valve is integral to the wye fitting located in
the washer plumbing between the cowl plenum
washer hose and the front washer nozzles, and is
concealed beneath the cowl plenum cover/grille panel
at the base of the windshield.
²Front Washer Nozzle- Two fluidic front
washer nozzles are secured with integral snap fea-
tures to dedicated openings in the cowl plenum cover/
grille panel located near the base of the windshield.
²Front Washer Plumbing- The plumbing for
the front washer system consists of rubber hoses and
molded plastic fittings. The plumbing is routed along
the left side of the engine compartment from the
washer reservoir, and through the dash panel into
the cowl plenum to the front washer nozzle fittings
beneath the cowl plenum cover/grille panel.
²Front Washer Pump/Motor- The front washer
pump/motor unit is located in a dedicated hole on the
lower outboard side of the washer reservoir, behind
the inner fender liner ahead of the left front wheel.
The front washer pump is located ahead of and below
the rear washer pump.
²Front Wiper Arm- The two front wiper arms
are secured with nuts to the threaded studs on the
ends of the two wiper pivot shafts, which extend
through the cowl plenum cover/grille panel located
near the base of the windshield.
²Front Wiper Blade- The two front wiper
blades are secured to the two front wiper arms with
an integral latch, and are parked on the glass near
the bottom of the windshield when the front wiper
system is not in operation.
²Front Wiper Module- The front wiper pivot
shafts are the only visible components of the front
wiper module. The remainder of the module is con-
cealed within the cowl plenum beneath the cowl ple-
num cover/grille panel. The front wiper module
includes the module bracket, four rubber-isolated
wiper module mounts, the front wiper motor, the
wiper motor crank arm, the two wiper drive links,
and the two front wiper pivots.
²Rain Sensor Module- Models equipped with
the optional automatic wiper feature have a Rain
Sensor Module (RSM) located behind a trim cover on
a bracket bonded to the inside surface of the wind-
shield glass, just above the inside rear view mirror
mounting button.
²Right Multi-Function Switch- The right
(wiper) multi-function switch is secured to the right
side of the multi-function switch mounting housing
near the top of the steering column, just below the
steering wheel. Only the control stalk for the right
multi-function switch is visible, while the remainder
of the switch is concealed beneath the steering col-
umn shrouds. The right multi-function switch con-tains all of the switches and control circuitry for both
the front and rear wiper and washer systems.
²Washer Fluid Level Switch- The washer fluid
level switch is located in a dedicated hole near the
center of the forward surface of the washer reservoir,
behind the left front wheel house splash shield.
²Washer Reservoir- The washer reservoir is
concealed between the left inner fender shield and
the left outer fender panel, behind the inner fender
liner and ahead of the left front wheel. The washer
reservoir filler neck is the only visible portion of the
reservoir, and it is accessed from the left front corner
of the engine compartment.
²Wiper High-Low Relay- The wiper high-low
relay is an International Standards Organization
(ISO) micro relay located in the Power Distribution
Center (PDC) in the engine compartment near the
battery.
²Wiper On-Off Relay- The wiper on-off relay is
an International Standards Organization (ISO) micro
relay located in the Power Distribution Center (PDC)
in the engine compartment near the battery.
Hard wired circuitry connects the front wiper and
washer system components to the electrical system of
the vehicle. These hard wired circuits are integral to
several wire harnesses, which are routed throughout
the vehicle and retained by many different methods.
These circuits may be connected to each other, to the
vehicle electrical system and to the front wiper and
washer system components through the use of a com-
bination of soldered splices, splice block connectors,
and many different types of wire harness terminal
connectors and insulators. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, further details on wire harness routing
and retention, as well as pin-out and location views
for the various wire harness connectors, splices and
grounds.
OPERATING MODES
The components of the front wiper and washer sys-
tem are designed to work in concert to provide the
following operating modes:
²Automatic Wiper- In models equipped with
the optional automatic wiper feature, the internal
circuitry of both the right (wiper) multi-function
switch, the rain sensor module, and the BCM work
in concert to provide an automatic wiper mode with
five sensitivity selections. The BCM tells the Rain
Sensor Module (RSM) when the automatic wiper
mode is selected and the manually selected sensitiv-
ity level, then the rain sensor module tells the BCM
each time enough water droplets have accumulated
within the wipe pattern on the windshield to require
front wiper operation. The BCM then automatically
WJFRONT WIPERS/WASHERS 8R - 3
FRONT WIPERS/WASHERS (Continued)

operates the front wipers at the programmed speed
and intervals requested by the RSM to maintain vis-
ibility through the windshield.
²Continuous Wipe Mode- The control knob on
the control stalk of the right (wiper) multi-function
switch has two continuous wipe positions, Low and
High. When selected, these switch positions will
cause the two-speed front wiper motor to operate in a
continuous low or high speed cycle.
²Headlamps On With Wipers- The BCM pro-
vides an automatic headlamps on with wipers feature
for models equipped with the optional automatic
headlamps. This is a customer programmable fea-
ture. If this feature is enabled, the headlamps will
turn on automatically when the windshield wipers
are turned on; and, if the headlamps were turned on
automatically when the wipers were turned on, they
will turn off automatically when the wipers are
turned off. In models equipped with the optional
automatic wiper feature, when the automatic wiper
mode is selected the headlamps will turn on auto-
matically only after the wipers complete three auto-
matic wipe cycles within about thirty seconds, and
they will turn off automatically after three minutes
elapse without any automatic wipe cycles. (Refer to 8
- ELECTRICAL/OVERHEAD CONSOLE - STAN-
DARD PROCEDURE - ELECTRONIC VEHICLE
INFORMATION CENTER PROGRAMMING).
²Mist Wipe Mode- The control stalk of the right
(wiper) multi-function switch has a momentary Mist
position. When selected, this switch position will
operate the front wipers in a low speed continuous
cycle for as long as the switch is held closed, then
will complete the current wipe cycle and park the
front wiper blades near the base of the windshield
when the switch is released.
²Speed Sensitive Intermittent Wipe Mode-
Except on models equipped with the optional auto-
matic wiper system, the internal circuitry of both the
right (wiper) multi-function switch and the BCM
work in concert to provide an intermittent wipe mode
with five delay interval selections. The BCM auto-
matically adjusts each manually selected delay inter-
val to compensate for vehicle speed.
²Washer Mode- When the momentary front
wash position of the control stalk for the right
(wiper) multi-function switch is selected with the
front wiper system operating in a continuous wipe
mode, washer fluid will be dispensed onto the wind-
shield glass through the washer nozzles for as long
as the washer switch is held closed. When the front
washer switch is actuated with the front wiper sys-
tem operating in an intermittent wipe mode, washer
fluid is still dispensed until the switch is released;
however, the front wipers will operate in a low speed
continuous cycle from the time the washer switch isclosed until several wipe cycles after the switch is
released, before returning to the selected intermit-
tent wipe mode.
²Wipe-After-Wash Mode- When the momentary
front wash position of the control stalk for the right
(wiper) multi-function switch is selected with the
front wiper system turned Off, the internal circuitry
of the BCM provides a wipe-after-wash feature.
When selected, this feature will operate the front
washer pump/motor and the front wipers for as long
as the front washer switch is held closed, then pro-
vide several additional wipe cycles after the switch is
released before parking the front wiper blades near
the base of the windshield.
OPERATION
The front wiper and washer system is designed to
provide the vehicle operator with a convenient, safe,
and reliable means of maintaining visibility through
the windshield glass. The various components of this
system are designed to convert electrical energy pro-
duced by the vehicle electrical system into the
mechanical action of the wiper blades to wipe the
outside surface of the glass, as well as into the
hydraulic action of the washer system to apply
washer fluid stored in an on-board reservoir to the
area of the glass to be wiped. When combined, these
components provide the means to effectively main-
tain clear visibility for the vehicle operator by remov-
ing excess accumulations of rain, snow, bugs, mud, or
other minor debris that might be encountered while
driving the vehicle under numerous types of inclem-
ent operating conditions from the outside windshield
glass surface.
The vehicle operator initiates all front wiper and
washer system functions with the control stalk of the
right (wiper) multi-function switch that extends from
the right side of the steering column, just below the
steering wheel. Rotating the control knob on the end
of the right (wiper) multi-function switch control
stalk selects the Off, Delay (on models not equipped
with the optional automatic wiper system), Auto (on
models equipped with the optional automatic wiper
system), Low, or High front wiper system operating
modes. In the Delay mode, the control knob also
allows the vehicle operator to select from one of five
intermittent wipe Delay intervals. In the Auto mode,
the control knob also allows the vehicle operator to
select from one of five automatic wiper sensitivity
levels. Pulling the right control stalk downwards
actuates the momentary front wiper system Mist
mode switch, while pulling the right control stalk
towards the steering wheel actuates the front washer
system switch. The multi-function switch provides
hard wired resistor multiplexed inputs to the Body
Control Module (BCM) for all of the front wiper sys-
8R - 4 FRONT WIPERS/WASHERSWJ
FRONT WIPERS/WASHERS (Continued)

ods may not prove conclusive in the diagnosis of the
Body Control Module (BCM), the Rain Sensor Mod-
ule (RSM), the Powertrain Control Module (PCM) or
the inputs to or outputs from these modules that con-
trol the various front wiper and washer system oper-
ating modes. The most reliable, efficient, and
accurate means to diagnose the BCM, the RSM, the
PCM or the BCM inputs and outputs related to the
various front wiper and washer system operating
modes requires the use of a DRBIIItscan tool. Refer
to the appropriate diagnostic information.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
FRONT WASHER SYSTEM
The diagnosis found here addresses an electrically
inoperative washer system. If the washer pump/mo-
tor operates, but no washer fluid is emitted from the
front washer nozzles, be certain to check the fluid
level in the reservoir. Also inspect the front washer
system components as required. (Refer to 8 - ELEC-
TRICAL/FRONT WIPERS/WASHERS - INSPEC-
TION). Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, details
of wire harness routing and retention, connector pin-
out information and location views for the various
wire harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Turn the ignition switch to the On position.
Turn the control knob on the control stalk of the
right (wiper) multi-function switch to the Low or
High wiper position. Check whether the front wiper
system is operating. If OK, go to Step 2. If not OK,
test and repair the front wiper system before con-
tinuing with these tests. Refer to FRONT WIPER
SYSTEM
(2) Turn the control knob on the control stalk of
the right (wiper) multi-function switch to the Off
position. Pull the control stalk of the right (wiper)
multi-function switch toward the steering wheel to
close the front washer switch. The front washer
pump should operate and the front wipers should
operate for about three sweep cycles after the switch
is released before they park. If the front wipers are
OK, but the front washers are not, go to Step 3. If
the front washers are OK, but the front wipers are
not, go to Step 5.
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the left headlamp and dash wire harness
connector for the front washer pump/motor from the
pump/motor connector receptacle. Check for continu-
ity between the ground circuit cavity of the left head-
lamp and dash wire harness connector for the front
washer pump/motor and a good ground. There should
be continuity. If OK, go to Step 4. If not OK, repair
the open ground circuit to ground (G106) as required.
(4) Reconnect the battery negative cable. Turn the
ignition switch to the On position. While pulling the
control stalk of the right (wiper) multi-function
switch toward the steering wheel to close the front
washer switch, check for battery voltage at the
washer pump switch sense circuit cavity of the left
headlamp and dash wire harness connector for the
front washer pump/motor unit. If OK, replace the
faulty front washer pump/motor. If not OK, repair
the open washer pump switch sense circuit between
the right (wiper) multi-function switch and the front
washer pump/motor unit as required.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the instrument panel wire harness con-
nector (Connector C2) for the Body Control Module
(BCM) from the BCM connector receptacle. Recon-
nect the battery negative cable. Turn the ignition
switch to the On position. While pulling the control
stalk of the right (wiper) multi-function switch
toward the steering wheel to close the front washer
WJFRONT WIPERS/WASHERS 8R - 7
FRONT WIPERS/WASHERS (Continued)

(4) Remove the six plastic nuts (2 short and 4
long) that secure the cowl grille cover to the studs on
the cowl top panel near the base of the windshield
(Fig. 3).
(5) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(6) Disconnect the engine compartment washer
hose from the cowl grille cover washer hose at the
plastic elbow connector.
(7) Remove the cowl grille cover from the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield.
(8) From the underside of the cowl grille cover, dis-
connect the washer hoses from the three barbed nip-
ples of the wye fitting/check valve unit.
(9) Remove the wye fitting/check valve unit from
the underside of the cowl grille cover.
INSTALLATION
(1) Position the wye fitting/check valve unit to the
underside of the cowl grille cover.
(2) From the underside of the cowl grille cover,
reconnect the three washer hoses to the barbed nip-
ples of the wye fitting/check valve unit.
(3) Reinstall the washer hoses for the front washer
nozzles into their routing clips on the underside of
the cowl grille cover.
(4) Position the cowl grille cover onto the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield
(Fig. 3).(5) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(6) Reconnect the cowl grille cover washer hose to
the engine compartment washer hose at the elbow
connector.
(7) Install the six plastic nuts that secure the cowl
grille cover to the studs on the cowl top panel near
the base of the windshield. These nuts are to be
installed by pushing them onto the studs in the fol-
lowing sequence:
(a) First, install the short nuts to the third stud
from the right, then the second stud from the left.
(b) Next, install the long nuts to the right out-
board stud, then the left outboard stud.
(c) Finally, install the two remaining long nuts
to the third stud from the left, then the second
stud from the right.
(8) Starting at the ends and working toward the
center, push the hood to plenum seal onto the for-
ward flanges of the cowl grille cover and the plenum
panel.
(9) Reinstall the wiper arms onto the wiper pivots.
(Refer to 8 - ELECTRICAL/FRONT WIPERS/WASH-
ERS/FRONT WIPER ARMS - INSTALLATION).
(10) Reconnect the battery negative cable.
FRONT WASHER HOSES/
TUBES
DESCRIPTION
The front washer plumbing consists of a small
diameter rubber hose that is routed from the barbed
outlet nipple of the front washer pump/motor on the
washer reservoir along the filler neck into the engine
compartment. In the engine compartment, a molded
plastic in-line fitting with barbed nipples joins the
washer hose to another section of hose that is routed
near the left headlamp and dash wire harness to the
cowl plenum area. The engine compartment washer
hose passes from the engine compartment into the
cowl plenum area through a dedicated hole with a
rubber grommet near the left end of the cowl plenum
panel. A molded plastic elbow fitting with barbed nip-
ples joins the engine compartment hose to the cowl
grille cover hose. The cowl grille cover washer hose is
routed through routing clips on the underside of the
cowl grille cover to a molded plastic wye fitting with
barbed nipples and an integral check valve. The cowl
grille cover hose is connected to one nipple on the
wye fitting and the two washer nozzle hoses are con-
nected to the other two wye fitting nipples. The
washer nozzle hoses are routed along the underside
of the cowl grille cover to the two washer nozzles.
Fig. 3 Cowl Grille Cover Remove/Install
1 - WASHER HOSE CONNECTION
2 - STUDS (6)
3 - COWL GRILLE COVER
4 - PLASTIC NUT (6)
8R - 10 FRONT WIPERS/WASHERSWJ
FRONT CHECK VALVE (Continued)

(4) Reinstall the washer hoses for the front washer
nozzle(s) into their routing clips on the underside of
the cowl grille cover.
(5) Position the cowl grille cover onto the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield
(Fig. 4).
(6) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(7) Reconnect the cowl grille cover washer hose to
the engine compartment washer hose at the elbow
connector.
(8) Install the six plastic nuts that secure the cowl
grille cover to the studs on the cowl top panel near
the base of the windshield. These nuts are to be
installed by pushing them onto the studs in the fol-
lowing sequence:
(a) First, install the short nuts to the third stud
from the right, then the second stud from the left.
(b) Next, install the long nuts to the right out-
board stud, then the left outboard stud.
(c) Finally, install the two remaining long nuts
to the third stud from the left, then the second
stud from the right.
(9) Starting at the ends and working toward the
center, push the hood to plenum seal onto the for-
ward flanges of the cowl grille cover and the plenum
panel.
(10) Close and latch the hood.
(11) Reinstall the wiper arms onto the wiper piv-
ots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/
WASHERS/FRONT WIPER ARMS -
INSTALLATION).
(12) Reconnect the battery negative cable.
FRONT WASHER PUMP/
MOTOR
DESCRIPTION
The front washer pump/motor unit is located on
the outboard side and near the front of the washer
reservoir, between the left front inner and outer
fender panels (Fig. 5). A small permanently lubri-
cated and sealed electric motor is coupled to the
rotor-type washer pump. A seal flange with a large
barbed inlet nipple on the pump housing passes
through a rubber grommet seal installed in one of
two dedicated mounting holes near the bottom of the
washer reservoir. The front washer pump/motor unit
is always mounted in the lower pump mounting hole
of the reservoir. A smaller barbed outlet nipple on the
pump housing connects the unit to the front washer
hose. The washer pump/motor unit is retained on the
reservoir by the interference fit between the barbedpump inlet nipple and the grommet seal, which is a
light press fit. An integral electrical connector recep-
tacle is located on the top of the motor housing. The
front washer pump/motor unit cannot be repaired. If
faulty or damaged, the entire washer pump/motor
unit must be replaced.
OPERATION
The front washer pump/motor unit is connected to
the vehicle electrical system through a single take
out and two-cavity connector of the left headlamp
and dash wire harness. The washer pump/motor is
grounded at all times through a take out of the left
headlamp and dash wire harness with a single eyelet
terminal connector that is secured under a ground
screw to the top of the left inner fender shield in the
engine compartment. The front washer pump/motor
receives battery current on a fused ignition switch
output (run-acc) circuit through the closed contacts of
the momentary front washer switch within the right
multi-function switch only when the switch control
stalk is pulled towards the steering wheel. Washer
fluid is gravity-fed from the washer reservoir to the
inlet side of the washer pump. When the pump motor
is energized, the rotor-type pump pressurizes the
washer fluid and forces it through the pump outlet
nipple, the front washer plumbing, and the front
washer nozzles onto the windshield glass.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
Fig. 5 Washer Pumps (Viewed from Bottom of
Reservoir)
1 - REAR WASHER PUMP/MOTOR
2 - FRONT WASHER PUMP/MOTOR
3 - WASHER FLUID LEVEL SWITCH
8R - 12 FRONT WIPERS/WASHERSWJ
FRONT WASHER NOZZLE (Continued)

(2) Raise and support the vehicle.
(3) Remove the liner from the left front fender
wheel house.
(4) Disconnect the left headlamp and dash wire
harness connector for the front washer pump/motor
from the motor connector receptacle (Fig. 6).
(5) Disconnect the washer hose from the barbed
outlet nipple of the front washer pump/motor and
allow the washer fluid to drain into a clean container
for reuse.
(6) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the barbed inlet nipple of
the washer pump out of the rubber grommet seal in
the reservoir. Care must be taken not to damage the
reservoir.
(7) Remove the rubber grommet seal from the
washer pump mounting hole in the washer reservoir
and discard.
INSTALLATION
(1) Install a new rubber grommet seal into the
washer pump mounting hole in the washer reservoir.
Always use a new rubber grommet seal on the reser-
voir.
(2) Position the barbed inlet nipple of the washer
pump to the rubber grommet seal in the reservoir
(Fig. 6).
(3) Press firmly and evenly on the washer pump
until the barbed inlet nipple is fully seated in the
rubber grommet seal in the washer reservoir mount-
ing hole.(4) Reconnect the washer hose to the barbed outlet
nipple of the washer pump.
(5) Reconnect the left headlamp and dash wire
harness connector for the front washer pump/motor
unit to the motor connector receptacle.
(6) Reinstall the liner into the left front fender
wheel house.
(7) Lower the vehicle.
(8) Refill the washer reservoir with the washer
fluid drained from the reservoir during the removal
procedure.
(9) Reconnect the battery negative cable.
FRONT WIPER ARM
DESCRIPTION
The front wiper arms are the rigid members
located between the wiper pivots that protrude from
the cowl plenum cover/grille panel near the base of
the windshield and the wiper blades on the wind-
shield glass. These wiper arms feature an over-center
hinge that allows easy access to the windshield glass
for cleaning. The wiper arm has a die cast metal
pivot end with a large mounting hole with internal
serrations at one end. A molded black plastic cap fits
over the wiper arm retaining nut to conceal the nut
and this mounting hole following wiper arm installa-
tion. The wide end of a tapered, stamped steel chan-
nel hinges on and is secured with a hinge pin to the
blade end of the wiper arm pivot end. One end of a
long, rigid, stamped steel strap, with a small hole
near its pivot end, is riveted and crimped within the
narrow end of the stamped steel channel. The tip of
the wiper blade end of this strap is bent back under
itself to form a small hook. Concealed within the
stamped steel channel, one end of a long spring is
engaged with a wire hook on the underside of the die
cast pivot end, while the other end of the spring is
hooked through the small hole in the steel strap. The
entire wiper arm has a satin black finish applied to
all of its visible surfaces.
A wiper arm cannot be adjusted or repaired. If
damaged or faulty, the entire wiper arm unit must be
replaced.
OPERATION
The front wiper arms are designed to mechanically
transmit the motion from the wiper pivots to the
wiper blades. The wiper arm must be properly
indexed to the wiper pivot in order to maintain the
proper wiper blade travel on the glass. The mounting
hole formation with internal serrations in the wiper
arm pivot end interlocks with the serrations on the
outer circumference of the wiper pivot driver, allow-
ing positive engagement and finite adjustment of this
Fig. 6 Washer Pumps (Viewed from Bottom of
Reservoir)
1 - REAR WASHER PUMP/MOTOR
2 - FRONT WASHER PUMP/MOTOR
3 - WASHER FLUID LEVEL SWITCH
WJFRONT WIPERS/WASHERS 8R - 13
FRONT WASHER PUMP/MOTOR (Continued)

formations that grip the wiper blade element. Also
included in this unit is the latching, molded plastic
pivot block that secures the superstructure to the
wiper arm. All of the metal components of the wiper
blade have a satin black finish applied.
²Element- The wiper element or squeegee is the
resilient rubber member of the wiper blade that con-
tacts the glass.
²Flexor- The flexor is a rigid metal component
running along the length of each side of the wiper
element where it is gripped by the claws of the
superstructure.
All Grand Cherokee models have two 52.50 centi-
meter (20.67 inch) long windshield wiper blades with
non-replaceable rubber elements (squeegees). The
wiper blades cannot be adjusted or repaired. If faulty,
worn, or damaged the entire wiper blade unit must
be replaced.
OPERATION
The wiper blades are moved back and forth across
the glass by the wiper arms when the wipers are
being operated. The wiper blade superstructure is
the flexible frame that grips the wiper blade element
and evenly distributes the force of the spring-loaded
wiper arm along the length of the element. The com-
bination of the wiper arm force and the flexibility of
the superstructure makes the element conform to
and maintain proper contact with the glass, even as
the blade is moved over the varied curvature found
across the glass surface. The wiper element flexor
provides the claws of the blade superstructure with a
rigid, yet flexible component on the element which
can be gripped. The rubber element is designed to be
stiff enough to maintain an even cleaning edge as it
is drawn across the glass, but resilient enough to
conform to the glass surface and flip from one clean-
ing edge to the other each time the wiper blade
changes directions.
REMOVAL
NOTE: The notched retainer end of the wiper ele-
ment should always be oriented towards the end of
the wiper blade that is nearest to the wiper pivot.
(1) Lift the front wiper arm to raise the wiper
blade and element off of the glass, until the wiper
arm hinge is in its over-center position.
(2) To remove the wiper blade from the wiper arm,
push the pivot block latch release tab under the tip
of the arm and slide the blade away from the tip
towards the pivot end of the arm far enough to dis-
engage the pivot block from the hook (Fig. 10).
(3) Extract the hook formation on the tip of the
wiper arm from the opening in the wiper blade
superstructure ahead of the wiper blade pivot block/
latch unit.
CAUTION: Do not allow the wiper arm to spring
back against the glass without the wiper blade in
place or the glass may be damaged.
(4) Gently lower the wiper arm tip onto the glass.
INSTALLATION
NOTE: The notched retainer end of the wiper ele-
ment should always be oriented towards the end of
the wiper blade that is nearest to the wiper pivot.
(1) Lift the front wiper arm off of the windshield
glass, until the wiper arm hinge is in its over-center
position.
(2) Position the front wiper blade near the hook
formation on the tip of the arm with the notched
retainer for the wiper element oriented towards the
end of the wiper arm that is nearest to the wiper
pivot.
Fig. 9 Wiper Blade - Typical
1 - RELEASE TAB
Fig. 10 Wiper Blade Remove/Install - Typical
1 - RELEASE TAB
WJFRONT WIPERS/WASHERS 8R - 15
FRONT WIPER BLADE (Continued)

(3) Insert the hook formation on the tip of the
wiper arm through the opening in the wiper blade
superstructure ahead of the wiper blade pivot block/
latch unit far enough to engage the pivot block with
the hook (Fig. 10).
(4) Slide the wiper blade pivot block/latch up into
the hook formation on the tip of the wiper arm until
the latch release tab snaps into its locked position.
Latch engagement will be accompanied by an audible
click.
(5) Gently lower the wiper blade onto the glass.
FRONT WIPER MODULE
DESCRIPTION
The front wiper module is secured with four screws
through rubber isolators to the cowl plenum panel
beneath the cowl plenum cover/grille panel (Fig. 11).
The ends of the wiper pivot shafts that protrude
through dedicated openings in the cowl plenum cov-
er/grille panel to drive the wiper arms and blades are
the only visible components of the front wiper mod-
ule. The front wiper module consists of the following
major components:
²Bracket- The front wiper module bracket con-
sists of a long tubular steel main member that has a
stamped pivot bracket formation near each end
where the two wiper pivots are secured. A stamped
steel mounting plate for the wiper motor is secured
with welds near the center of the main member.
²Crank Arm- The front wiper motor crank arm
is a stamped steel unit with a slotted hole on the
driven end that is secured to the wiper motor outputshaft with a nut, and a ball stud secured to the drive
end.
²Linkage- Two stamped steel drive links con-
nect the wiper motor crank arm to the pivot lever
arms. The passenger side drive link has a plastic
socket-type bushing on each end. The driver side
drive link has a plastic socket-type bushing on one
end, and a plastic sleeve-type bushing on the other
end. The socket-type bushing on one end of each
drive link is snap-fit over the ball stud on the lever
arm of its respective pivot. The driver side drive link
sleeve-type bushing end is then fit over the motor
crank arm ball stud, and the other socket-type bush-
ing of the passenger side drive link is snap-fit over
the exposed end of the wiper motor crank arm ball
stud.
²Motor- The front wiper motor is secured with
three screws to the motor mounting plate near the
center of the wiper module bracket. The wiper motor
output shaft passes through a hole in the module
bracket, where a nut secures the wiper motor crank
arm to the motor output shaft. The two-speed perma-
nent magnet wiper motor features an integral trans-
mission, an internal park switch, and an internal
automatic resetting circuit breaker.
²Pivots- The two front wiper pivots are secured
to the ends of the wiper module bracket. The crank
arms that extend from the bottom of the pivot shafts
each have a ball stud on their end. The upper end of
each pivot shaft where the wiper arms will be fas-
tened each has an externally serrated drum with a
threaded stud secured to it.
The front wiper module cannot be adjusted or
repaired. If any component of the module is faulty or
damaged, the entire front wiper module unit must be
replaced. The reinforcement bracket and stud plate
are available for service replacement.OPERATION
The front wiper module operation is controlled by
the battery current inputs received by the wiper
motor from the wiper on/off and wiper high/low
relays. The wiper motor speed is controlled by cur-
rent flow to either the low speed or the high speed
set of brushes. The park switch is a single pole, sin-
gle throw, momentary switch within the wiper motor
that is mechanically actuated by the wiper motor
transmission components. The park switch alter-
nately closes the wiper park switch sense circuit to
ground or to battery current, depending upon the
position of the wipers on the glass. This feature
allows the motor to complete its current wipe cycle
after the wiper system has been turned Off, and to
park the wiper blades in the lowest portion of the
wipe pattern. The automatic resetting circuit breaker
protects the motor from overloads. The wiper motor
Fig. 11 Front Wiper Module
1 - FRONT WIPER MODULE
2 - SCREW (4)
3 - WIRE HARNESS CONNECTOR
4 - LOWER COWL PLENUM PANEL
8R - 16 FRONT WIPERS/WASHERSWJ
FRONT WIPER BLADE (Continued)

crank arm, the two wiper linkage members, and the
two wiper pivots mechanically convert the rotary out-
put of the wiper motor to the back and forth wiping
motion of the wiper arms and blades on the glass.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the front wiper arms from the wiper
pivots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/
WASHERS/FRONT WIPER ARMS - REMOVAL).
(3) Unlatch and open the hood.
(4) Remove the hood to plenum seal from the for-
ward flanges of the cowl grille cover and the plenum
panel.
(5) Remove the six plastic nuts (2 short and 4
long) that secure the cowl grille cover to the studs on
the cowl top panel near the base of the windshield
(Fig. 12).
(6) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(7) Disconnect the front washer engine compart-
ment hose from the cowl grille cover hose at the
elbow connector.
(8) Remove the cowl grille cover from the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield.
(9) Remove the four screws that secure the front
wiper module to the cowl plenum panel (Fig. 13).
(10) Lift the left end of the front wiper module far
enough to access the front wiper motor wire harness
connector.(11) Disconnect the left headlamp and dash wire
harness connector for the front wiper motor from the
front wiper motor pigtail wire connector.
(12) Remove the front wiper module from the cowl
plenum as a unit.
INSTALLATION
(1) Position the front wiper module into the cowl
plenum as a unit (Fig. 13).
(2) Lift the left end of the front wiper module far
enough to access the front wiper motor wire harness
connector.
(3) Reconnect the left headlamp and dash wire
harness connector for the front wiper motor to the
front wiper motor pigtail wire connector.
(4) Loosely install one of the front wiper module
mounting screws to the mounting hole near the pivot
on the right end of the module to locate the module
in the plenum.
(5) Working from left to right, install and tighten
the four screws that secure the front wiper module to
the cowl plenum panel. Tighten the screws to 8 N´m
(72 in. lbs.).
(6) Position the cowl grille cover onto the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield
(Fig. 12).
(7) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(8) Reconnect the front washer system engine com-
partment hose to the cowl grille cover hose at the
elbow connector.
Fig. 12 Cowl Grille Cover Remove/Install
1 - WASHER HOSE CONNECTION
2 - STUDS (6)
3 - COWL GRILLE COVER
4 - PLASTIC NUT (6)
Fig. 13 Front Wiper Module Remove/Install
1 - FRONT WIPER MODULE
2 - SCREW (4)
3 - WIRE HARNESS CONNECTOR
4 - LOWER COWL PLENUM PANEL
WJFRONT WIPERS/WASHERS 8R - 17
FRONT WIPER MODULE (Continued)

(9) Install the six plastic nuts that secure the cowl
grille cover to the studs on the cowl top panel near
the base of the windshield. These nuts are to be
installed by pushing them onto the studs in the fol-
lowing sequence:
(a) First, install the short nuts to the third stud
from the right, then the second stud from the left.
(b) Next, install long nuts to the right outboard
stud, then the left outboard stud.
(c) Finally, install the two remaining long nuts
to the third stud from the left, then the second
stud from the right.
(10) Starting at the ends and working toward the
center, push the hood to plenum seal onto the for-
ward flanges of the cowl grille cover and the plenum
panel.
(11) Close and latch the hood.
(12) Reinstall the wiper arms onto the wiper piv-
ots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/
WASHERS/FRONT WIPER ARMS -
INSTALLATION).
(13) Reconnect the battery negative cable.
RAIN SENSOR MODULE
DESCRIPTION
The Rain Sensor Module (RSM) is the primary
component of the automatic wiper system (Fig. 14).
The RSM is located on the inside of the windshield,
between the rear view mirror mounting button and
the windshield header and is concealed behind a
molded plastic trim cover that snaps over the modulehousing. The triangular-shaped molded black plastic
housing of the RSM has a rectangular opening
located on the upper end of the housing for the mod-
ule connector receptacle, which contains four termi-
nal pins. These terminal pins connect the rain sensor
to the vehicle electrical system through a dedicated
take out and connector of the overhead wire harness
that extends from above the headliner. Five openings
on the windshield side of the RSM housing are fitted
with eight convex clear plastic lenses. A metal spring
clip on each side of the housing near the bottom
secures the RSM to a plastic mounting bracket that
is bonded to the windshield glass. Concealed within
the RSM housing is the electronic circuitry of the
module, which includes four InfraRed (IR) diodes,
two photocells, and a microprocessor.
The RSM software is Flash compatible, which
means it can be reprogrammed using Flash repro-
gramming procedures. However, if any of the hard-
ware of the RSM is damaged or faulty, the entire
module must be replaced. The RSM bracket is ser-
viced as a unit with the windshield glass. If the
bracket is faulty, damaged, or separated from the
windshield glass, the windshield unit must be
replaced.
OPERATION
The microprocessor-based Rain Sensor Module
(RSM) senses moisture in the wipe pattern on the
outside of the windshield glass and sends wipe com-
mands to the Body Control Module (BCM). Four
InfraRed (IR) diodes within the RSM generate IR
light beams that are aimed by four of the convex
optical lenses near the base of the module through
the windshield glass. Four additional convex optical
lenses near the top of the RSM are focused on the IR
light beams on the outside of the windshield glass
and allow the two photocells within the module to
sense changes in the intensity of these IR light
beams. When sufficient moisture accumulates within
the wipe pattern of the windshield glass, the RSM
detects a change in the monitored IR light beam
intensity.
The internal programming of the RSM then sends
the appropriate electronic wipe command messages
to the BCM over the Programmable Communications
Interface (PCI) data bus. The BCM responds by acti-
vating or deactivating the front wiper system. The
BCM also sends electronic sensitivity level messages
to the RSM over the PCI data bus based upon the
driver-selected sensitivity setting of the control knob
on the control stalk of the right (wiper) multi-func-
tion switch. The higher the selected sensitivity set-
ting the more sensitive the RSM is to the
accumulated moisture on the windshield glass, and
Fig. 14 Rain Sensor Module
1 - SPRING CLIP (2)
2 - INFRARED LENS (4)
3 - HOUSING
4 - CONNECTOR RECEPTACLE
5 - PHOTOCELL LENS (4)
8R - 18 FRONT WIPERS/WASHERSWJ
FRONT WIPER MODULE (Continued)